The Shop > Metal Stuff
would this brazing wire effectively connect copper to stainless steel?
bogstandard:
As far as I know, standard plumbing copper tube hasn't the correct wall thickness for boiler making, it is much too thin.
Normally you have to buy specially drawn material to get the thicker wall thicknesses. The end flanges are usually made from the same thickness, or thicker material as used for the boiler shell tube. The end caps are then formed over hardwood or metal forms to give the correct radii to the corners and correct surface areas for the silver solder to bond to, ensuring the joint is at least as strong, if not stronger than the parent metal.
You will also required phos bronze stays to stop the end caps bowing out and deforming, and ALL boiler fittings in the boiler should be of phos bronze. Brass is a nono for correct use in a boiler, the zinc leeches out of the brass over time and it becomes a very weak and porous material.
It also has to be subjected to pressure testing to obtain it's certificate, and I think at the moment that has to be renewed and tested each second year. I am not positive as to the timeline but it does work like that.
Welded steels are subject to even more rigorous regulations.
How do I know all this.
I only gave up making model boilers a few years ago, but some things have been relaxed slightly since then.
Because of all the regulations and insurance requirements needed nowadays, it would be a lot easier for me to go out and buy a commercially produced one.
A lot of people do still make their own boilers, mainly because of cost, or the self satisfaction of making one. But again they have to conform to rigid standards to be acceptable for use.
If a high pressure boiler is to be used in a public place, it must have all the necessary certificates and insurance in place before it can be steamed. A public place is an area where anyone other than yourself is operating the boiler, so that includes your kitchen or anywhere else in your home when family members are about.
People scream and say 'I will do what I want in my own home'. Wrong, the law will just make sure that whoever is hurt, screws you for as much cash as they can get, whether that is your parents, kids, wife or just a visitor.
Making a boiler brings out the worst in people when it is discussed on a forum. The above is only the basics, you will still get people saying that such and such is OK for making a boiler, because I have never had one blow up. Maybe they are right, or just plain lucky. To me, if it doesn't conform to national and local, plus insurance regulations, you shouldn't do it.
BTW, there are different regulations concerning 'toy' boilers, Mamod, Wilesco etc., I don't know what they are, but I am sure someone will soon let us know. Maybe Steve (Cedge) can give us an insight into that, as he deals a lot with a model steam engine company.
Bogs
jonogt:
on the wall thickness thing:
http://www.homemodelenginemachinist.com/index.php?topic=2092.0
someone posted that link in another of my threads as an excellent boiler construction example, and I took note on the piece of tube he's using. It looks like the wall is 0.05 inches thick... 0.06 at most. the piece I have is just over 0.09 inches thick, and has a working pressure of150 PSI at 400' F (found on plumbing charts). I'm not saying his material is too thin, and I'm not saying that you're wrong... I'm just perplexed. Were you assuming my piece of tubing was thinner?
Thanks for the tip on brass being a no-no. I'll do something else.
For safety and legality: however I end up building this thing, I'll definately be the only one around (hiding behind a barrier) until it's proven multiple times to hold atleast double the pressure I'll be running.
On the actual pressure: How high do people usually take these things? I was planning to have it go to 30 PSI max (test it to 60). I read somewhere else about somebody pushing their's to 200!
-Jon
sbwhart:
Jon
Can I point you to a good book on the subject of model boilers:- This is the book
http://www.amazon.com/Model-locomotive-boilers-design-construction/dp/B0000EG5PO/ref=sr_1_2?ie=UTF8&s=books&qid=1238609678&sr=1-2
I got mine from ebay its got the correct formulae for working out thickness etc
A little research doesn't go amiss
For model locomotives the working pressure is 60 to 80 psi thats for a 2 1/2" to 5" gauge loco
Cheers
Stew
bogstandard:
--- Quote ---I'm just perplexed. Were you assuming my piece of tubing was thinner?
--- End quote ---
Yes, the reason being in your next quote.
--- Quote ---plumbing contractor store half a block away told me that they had cut off the ends on a few of their 40 foot lengths
--- End quote ---
My statement to verify the above.
--- Quote ---As far as I know, standard plumbing copper tube hasn't the correct wall thickness for boiler making, it is much too thin
--- End quote ---
I was wrong, having assumed you had standard plumbing pipe. If you had mentioned the thickness, that statement wouldn't have appeared.
You will also notice, that Firebird (who I am still in regular contact with) on the HMEM site, was directed by myself, to someone who was more up to date with current regulations than myself. Because, as I stated, I hadn't made a boiler recently, and I wished him to have the most up to date legislation. Unfortunately we have no up to date boiler people on here (as far as I know). So it is up to you to find out all about it for yourself.
With my post, I was trying to get thru to you that building a boiler shouldn't be taken lightly, but a lot of research has to go into it before carrying on with your build. The main reason, when you first started out on this topic, I am sure by what you had written and the questions you posed, you were quite willing to bang a few raggedy bits and pieces together and hope it worked.
It now looks like, now you have had the riot act quoted to you, maybe you will take a bit of advice and do it correctly. Rather than taking the law into your own hands.
If that decision was because of my posting about it, and telling it as it should be, then I stand by every word I said.
Also, if you read the site disclaimer, the onus is on yourself to check things out, nothing you see on here should be taken as gospel. We are only advisors.
The last thing any member on here wants to see is yourself, or the people around you, being injured, for the lack of a little safety information or warning about what you want to achieve.
Bogs
PTsideshow:
As everything that already has been said in this thread and the pressure cooker thread.
Here is the section of the Michigan code. Section 408.757c Miniature hobby locomotive; annual inspection; report; fee; rules; application and inspection by club; “public display or use” defined.
http://www.legislature.mi.gov/(S(mwfxd1rwxyqu2nal5hfnvu45))/mileg.aspx?page=getobject&objectname=mcl-act-290-of-1965&queryid=39491&highlight=is the link to the code and various sections.
All most all states have a code of some kind now.
againhttp://www.doli.state.mn.us/boilerohio.html this is the link to an antique boiler disaster in Ohio. The forces that were let loose are something to ponder.
I'm sure that your state has something similar. You just have to find it,
glen
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